The invention relates to an electron window for a liquid-metal anode in the form of a membrane, with a liquid-metal anode which has an electron window according to the invention and an X-radiator with such a liquid-metal anode. The invention also relates to a method for operating an X-radiators with a liquid-metal anode.
Liquid-metal anodes have been used since recently to produce X-ray beams. This technique is called LIMAX (liquid-metal anode X-ray). When producing X-ray beams the liquid-metal anode is bombarded with an electron beam. As a result the liquid-metal anode heats up considerably-like any known solid anode. The heat that forms must be removed from the region of focus in order that the anode does not overheat. This takes place in liquid-metal anodes by means of turbulent mass transport, convection, heat-conduction and electron diffusion processes. In the region of focus in which the electrons strike the liquid-metal anode, the line system of the liquid-metal anode has an electron window. This consists of a thin metal foil or a diamond film which is so thin that in it the electrons lose only a small part of their kinetic energy. In order to be able to remove the heat that forms below the electron window, the liquid metal is circulated in a circuit. The heat that forms at the location of the focus is thus entrained by the liquid metal. The problem arises with the required thin metal foil that it can become unstable or even burst if the liquid pressure or the shearing stress exceed a predetermined mechanical limit.